Plastic film applicator with a braking function

ABSTRACT

A plastic film applicator includes an applicator body including a mandrel and a grip connected to the mandrel, and a brake device including a bearing ring detachably mounted between the mandrel and grip of the applicator body for enabling the elastic braking pad to be biased toward the applicator body by an external force and an elastic braking pad having one end thereof connected to the bearing ring and elastically biasable by an external force. After the user attached a plastic film roll onto the mandrel of the applicator body, the user can press the thumb on the elastic braking pad to timely force the elastic braking pad toward the plastic film roll, forcing the abutment protrusion of the elastic braking pad into abutment against the film roll shaft, and thus, a braking effect is provided to the film roll shaft to stretch the extended plastic film for wrapping.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to plastic film application technology, and more particularly to a plastic film applicator with a braking function.

2. Description of the Related Art

When using a plastic film roll for wrapping goods, the plastic film must be stretched to produce a certain tension so that the plastic film can be positively wrapped about the goods. According to conventional techniques, the user needs to give a certain contact force to the plastic film of the plastic film roll to provide a certain brake effect, keeping the extended plastic film in a stretched status for wrapping. But for the user, due to standing posture, it is inconvenient to brake the plastic film roll directly with the hand in the actual operation, and the tension of the extended plastic film can be insufficient, affecting the wrapping.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a plastic film applicator for the application of a plastic film roll, which provides a braking function to enhance application convenience.

To achieve this and other objects of the present invention, a plastic film applicator comprises an applicator body and a brake device. The applicator body comprises a mandrel, and a grip connected to one end of the mandrel. The brake device comprises a bearing ring and an elastic braking pad. The bearing ring is detachably mounted between the mandrel and grip of the applicator body for enabling the elastic braking pad to be biased toward the applicator body by an external force.

Thus, after the user attached a plastic film roll onto the mandrel of the applicator body into abutment at the bearing ring of the brake device, the user can hold the grip of the applicator body for allowing the plastic film roll to be rotated relative to the applicator body so that the plastic film of the plastic film roll can be extended out for wrapping. During wrapping, the user can press the thumb on the elastic braking pad to timely force the elastic braking pad toward the plastic film roll, forcing the abutment protrusion of the elastic braking pad into abutment against the film roll shaft, and thus, a braking effect is provided to the film roll shaft to stretch the extended plastic film for wrapping.

Preferably, the applicator body further comprises a flange extended around the periphery of the connection area between the mandrel and the grip. The bearing ring of the brake device is abutted against the flange of the applicator body. Further, the flange of the applicator body comprises a positioning recess; the bearing ring of the brake device comprises a positioning protruding portion. When the bearing ring of the brake device is abutted against the flange of the applicator body, the positioning protruding portion of the brake device is engaged into the positioning recess of the flange of the applicator body to stop the brake device from rotation relative to the applicator body.

Preferably, the mandrel of the applicator body comprises a stopping protrusion protruded from the periphery thereof adjacent to the flange. Further, the bearing ring of the brake device comprises a recessed portion. When the bearing ring of the brake device is abutted at the flange of the applicator body, the recessed portion of the brake device is engaged with the stopping protrusion of the mandrel of the applicator body to stop the brake device from axial displacement relative to the applicator body.

Preferably, the elastic braking pad of the brake device comprises an abutment protrusion located on one side thereof facing toward the bearing ring. When the elastic braking pad is biased by an external force, the applied force is concentrated onto the abutment protrusion against the plastic film roll.

Preferably, the elastic braking pad of the brake device comprises an anti-slip grain pattern located on one side thereof opposite to the bearing ring for enabling the user to apply a force to the elastic braking pad conveniently.

Preferably, the applicator body comprises a hanging hole disposed near a distal end thereof remote from the mandrel for allowing handing of the plastic film applicator when it is not in use.

Preferably, the applicator body further comprises an anti-escape end-piece located on an opposite end of the mandrel remote from the grip for stopping the plastic film roll from escaping out of the mandrel of the applicator body.

Other advantages and features of the present invention will be fully understood by reference to the following specification in conjunction with the accompanying drawings, in which like reference signs denote like components of structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an oblique top elevational view of a plastic film applicator in accordance with the present invention.

FIG. 2 is an exploded view of a part of the plastic film applicator in accordance with the present invention.

FIG. 3 is a sectional view of a part of the present invention, illustrating the structural relationship between the flange of the applicator body and the bearing ring.

FIG. 4 is an applied view of the present invention, illustrating a plastic film roll attached to the plastic film applicator.

FIG. 5 is a longitudinal sectional view of FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 4, a plastic film applicator 10 in accordance with the present invention is shown. The plastic film applicator 10 is configured for the application of a plastic film roll 12. As illustrated, the plastic film roll 12 comprises a film roll shaft 14, and a roll of plastic film 16 wound round the film roll shaft 14. As illustrated in FIGS. 1 and 2, the plastic film applicator 10 comprises an applicator body 20 and a brake device 30.

The applicator body 20 is made of an elastic material (such as, plastics), comprising a mandrel 21, a grip 23 coaxially connected to one end of the mandrel 21, and a flange 25 extended around the periphery of the junction between the mandrel 21 and the grip 23.

The mandrel 21 has two stopping protrusions 22 located on the outer periphery thereof at two opposite sides. The grip 23 has a hanging hole 24 located at one end thereof remote from the mandrel 21. The flange 25 defines two opposing positioning recesses 26 respectively disposed adjacent to the two stopping protrusions 22 of the mandrel 21. The applicator body 20 further comprises an anti-escape end-piece 27 located at one end of the mandrel 21 remote from the grip 23. As illustrated in FIG. 5, the maximum outer diameter R1 of the anti-escape end-piece 27 is larger than the outer diameter R2 of the mandrel 21. The film roll shaft 14 is a tubular shaft. The inner diameter R3 of the film roll shaft 14 is in the range between the maximum outer diameter R1 of the anti-escape end-piece 27 and the outer diameter R2 of the mandrel 21 of the applicator body 20.

The brake device 30 is made of an elastic material (such as, plastics), comprising a bearing ring 40 and an elastic braking pad 50. The inner diameter R4 of the bearing ring 40 is equal to the outer diameter R2 of the mandrel 21 of the applicator body 20. The bearing ring 40 comprises two recessed portions 41 respectively located on a top edge thereof at two opposite sides, and two positioning protruding portions 42 respectively downwardly extended from an opposing bottom edge thereof at two opposite sides corresponding to the respective recessed portions 41. The elastic braking pad 50 has one end thereof connected to the bearing ring 40 and spaced from the recessed portions 41 and positioning protruding portions 42 of the bearing ring 40 at 90-degrees angle. Further, the elastic braking pad 50 has an anti-slip grain pattern 51 located on a back side thereof opposite to the bearing ring 40 for allowing the user to apply a pressing pressure to the elastic braking pad 50 positively, and an abutment protrusion 52 located on an opposing front side thereof and facing toward the bearing ring 40. When the user presses the elastic braking pad 50, the applied force can be concentrated onto the abutment protrusion 52.

In installation, due to that the inner diameter R4 of the bearing ring 40 of the brake device 30 is smaller than the maximum outer diameter R1 of the anti-escape end-piece 27 of the applicator body 20, the bearing ring 40 of the brake device 30 is elastically deformed and radially expanded when it is moved over the anti-escape end-piece 27 of the applicator body 20. After moved over the anti-escape end-piece 27 of the applicator body 20, the brake device 30 is moved along the axis of the applicator body 20 toward the flange 25 of the applicator body 20. The angular position of the brake device 30 is properly adjusted to aim the positioning protruding portions 42 at the respective positioning recesses 26 of the flange 25. When the bearing ring 40 of the brake device 30 touches the stopping protrusions 22 of the mandrel 21 of the applicator body 20, a pressure must be applied to the brake device 30 against the interference between the brake device 30 and the stopping protrusions 22, causing the bearing ring 40 of the brake device 30 to expand radially so that the bearing ring 40 of the brake device 30 can be moved over the stopping protrusions 22 of the mandrel 21 of the applicator body 20 and then abutted against the flange 25 of the applicator body 20, as illustrated in FIG. 2 and FIG. 3. At this time, on the one hand the positioning protruding portions 42 of the brake device 30 are respectively engaged in the respective positioning recesses 26 of the flange 25 of the applicator body 20 to stop the brake device 30 from rotation relative to the applicator body 20, on the other hand the recessed portions 41 of the bearing ring 40 are respectively engaged with the stopping protrusions 22 of the mandrel 21 of the applicator body 20 to stop the brake device 30 from axial displacement relative to the applicator body 20, and thus, the applicator body 20 and the brake device 30 are assembled.

When using the plastic film applicator 10 to apply a plastic film roll 12, as illustrated in FIG. 4 and FIG. 5, due to that the inner diameter R3 of the film roll shaft 14 of the plastic film roll 12 is smaller than the maximum outer diameter R1 of the anti-escape end-piece 27 of the applicator body 20, forcing the film roll shaft 14 of the plastic film roll 12 to move over the anti-escape end-piece 27 of the applicator body 20 can compress the anti-escape end-piece 27 of the applicator body 20 radially so that the film roll shaft 14 can pass over the anti-escape end-piece 27. After passed over the anti-escape end-piece 27 of the applicator body 20, release the pressure from the plastic film roll 12. At this time, the anti-escape end-piece 27 of the applicator body 20 immediately returns to its previous shape to stop the plastic film roll 12 from escaping out of the mandrel 21 of the applicator body 20. After attached the plastic film roll 12 onto the mandrel 21, move the plastic film roll 12 axially along the applicator body 20 toward the brake device 30 till that the bottom end of the film roll shaft 14 is abutted at the bearing ring 40 of the brake device 30. A this time, the user can hold the grip 23 of the applicator body 20 for allowing the plastic film roll 12 to be rotated relative to the applicator body 20 so that the plastic film of the plastic film roll 12 can be extended out for wrapping. During wrapping, the user can press the thumb on the elastic braking pad 50 to timely force the elastic braking pad 50 toward the plastic film roll 12, forcing the abutment protrusion 52 of the elastic braking pad 50 into abutment against the film roll shaft 14, and thus, a braking effect is provided to the film roll shaft 14 to stretch the extended plastic film for wrapping.

In conclusion, the plastic film applicator 10 of the present invention allows the user to operate and to brake the plastic film roll 12 conveniently with one single hand. Through the elastic braking pad 50, the applied force can be effectively concentrated to provide a good braking effect to the plastic film roll 12. After the use, the user can use the hanging hole 24 of the applicator body 20 to hang the plastic film applicator 10 on, for example, a nail at a wall. 

What is claimed is:
 1. A plastic film applicator, comprising: an applicator body comprising a mandrel and a grip connected to one end of said mandrel; and a brake device comprising a bearing ring and an elastic braking pad, said bearing ring being detachably mounted between said mandrel and said grip of said applicator body for enabling said elastic braking pad to be biased toward said applicator body by an external force.
 2. The plastic film applicator as claimed in claim 1, wherein said applicator body further comprises a flange extended around the periphery of the connection area between said mandrel and said grip, said bearing ring of said brake device being abutted against said flange of said applicator body.
 3. The plastic film applicator as claimed in claim 2, wherein said flange of said applicator body comprises a positioning recess; said bearing ring of said brake device comprises a positioning protruding portion engaged into said positioning recess of said flange of said applicator body.
 4. The plastic film applicator as claimed in claim 2, wherein said mandrel of said applicator body comprises a stopping protrusion protruded from the periphery thereof adjacent to said flange; said bearing ring of said brake device comprises a recessed portion engaged with said stopping protrusion of said mandrel of said applicator body.
 5. The plastic film applicator as claimed in claim 1, wherein said elastic braking pad of said brake device comprises an abutment protrusion located on one side thereof facing toward said bearing ring.
 6. The plastic film applicator as claimed in claim 1, wherein said elastic braking pad of said brake device comprises an anti-slip grain pattern located on one side thereof opposite to said bearing ring.
 7. The plastic film applicator as claimed in claim 1, wherein said grip of said applicator body comprises a hanging hole disposed near a distal end thereof remote from said mandrel.
 8. The plastic film applicator as claimed in claim 1, wherein said applicator body further comprises an anti-escape end-piece located on an opposite end of said mandrel remote from said grip. 